1. Field of the Invention
The present invention relates to a semiconductor device manufacturing method, a wafer treatment system, and a recording medium.
2. Description of the Related Art
Conventionally, when treating wafers in such a manufacturing apparatus as an etching one, it has been required to load a predetermined number of wafers in such a container as an FOUP (Front Opening Unified Pod) and transfer the container among manufacturing apparatuses. Each time such a container is loaded in a manufacturing apparatus, the door of the container is opened and wafers are unloaded from the container, then subjected to the treatment in the manufacturing apparatus one by one. When the treatment is finished, the wafers are reloaded into the container sequentially. And when all the subject wafers are loaded in the container, the door is closed and the container is transferred to the manufacturing apparatus in the next process. Those wafers loaded in such a container have been subjected to, for example, a clean gas blowing process according to the conventional technique (e.g., the patent document 1 (JP-A -2004-311940)).
The patent document 2 (JP-A-2006-128153) describes a configuration of an apparatus that removes contaminants, etc. from wafers loaded in a pod by blowing such a clean gas to the top surfaces of those wafers through a gas supply pipe disposed in the upper portion of an internal opening according to the FIMS (Front-opening Interface Mechanical Standard).
On the other hand, the patent document 3 (JP-A-2006-351868) describes a configuration of another apparatus that includes a substrate W treatment unit and a base used to mount a container C for loading plural substrates W. In the container C are disposed those substrates W substantially horizontally and in layers vertically. The container C is provided with an opening used to load/unload the substrates W therein/therefrom at its one side. Outside the opening are provided plurality of gas supply holes and each of those gas supply holes is oriented so as to supply the gas substantially horizontally to each space between the substrates in the container C. This configuration is effective to remove the extraneous particles adhered inside the carrier and those adhered to the wafers in the carrier.
Furthermore, the patent document 4 (JP-A-2002-261159) describes a substrate transfer container provided with an air cleaner or dehumidifier used to remove the water content, etc. from the air supplied in the manufacturing processes of semiconductor chips with use of a low dielectric constant insulation film.
Furthermore, conventional dry-etching processes have often been confronted with a problem that foreign matters are generated at the bottoms of recessed portions if such a recessed portion as a wiring groove, a via hole, or a contact hole is formed in an interlayer insulation film, for example, on a wafer with use of a stopper, which is an etching stop film that contains nitrogen.
As a result of careful examinations, the present inventor et al have found that generation of such foreign matters is caused by a gas (degas) generated by reaction between the etching gas used in such a dry-etching process and the etching object film. And the present inventor et al. have also found that purging to be carried out for wafers with use of another gas just after the degas generation is very effective to reduce the degas concentration, thereby reducing the generation of those foreign matters. Therefore, the present inventor et al. have reviewed the purge gas blowing process for dry-etched wafers reloaded in the wafer container just after the dry-etching in the etching apparatus.
As a result, for example, as described in the patent document 2, in case of the method that blows out a purge gas from above the object wafers, it becomes impossible to apply the purge gas onto the surfaces of all the object wafers uniformly. And this makes it difficult to thin the degas generated from the wafers enough and difficult to suppress the generation of foreign matters at the bottoms of the via holes. This is why some improvement is still required for the method. Furthermore, in case of the method described in the patent document 3, which applies the purge gas horizontally to the object wafers, it is possible to suppress the generation of such foreign matters more than the method described in the patent document 2, which blows out the purge gas from above the object wafers. However, foreign matters are still generated on some wafers. Thus some improvement is also required for the method. And in case of the method described in the patent document 4, the water content can be removed while the wafers are transferred, but the method does not take any consideration how to lower the degas concentration that occurs just after the generation of the degas. This has also been a problem. In addition, the method described in the patent document 4 is also required to provide the wafer container with an air cleaner, a dehumidifier, etc. additionally. And in order to satisfy those requirements, the manufacturing cost rises and this has been another problem.